Download A Study of Serum Thyroid Stimulating Hormone and Prolactin Levels

International Journal of Science and Research (IJSR)
ISSN (Online): 2319-7064
Index Copernicus Value (2013): 6.14 | Impact Factor (2015): 6.391
A Study of Serum Thyroid Stimulating Hormone
and Prolactin Levels of Infertile Females
Dr .Omer Mohamed Shoaib1, Dr. ELhashimi E. Hassan2
1, 2
Department of Clinical Chemistry, Faculty of Medical Laboratory Sciences, Alzaeim Alazhari University -Sudan
Abstract: Background: Infertility represents a common condition nowadays, with important medical, economic and psychological
implications. Traditionally, measurement of Prolactin (PRL) and thyroid hormones, especially thyroid stimulating hormone (TSH) has
been considered an important component of infertility workup in females. Objective: The study was designed to evaluate the status of
thyroid function in infertile Sudanese females and to investigate the impact of thyroid status on serum prolactin level. Method: In this
retrospective case control study, we investigated seventy infertile females in the age range of 20- 40 years attending department of
Diagnostic and research unit at Khartoum teaching hospital for hormonal evaluation from March, 2014 to august, 2015. Thirty (30)
healthy fertile females with similar age range were selected as controls group. The association between thyroid dysfunction and levels of
serum Prolactin was reviewed. Results: In this study the results showed the means levels of TSH and T3 in study group were increased
than control group but statistically not significant, P value > 0.05 and the mean of T4 in the study group was significant increased than
control group < 0.05, while that the mean level of serum prolactin was significant decreased in the study group than control group.
Majority of infertile females were euthyroid and there was no significant association between Infertility & TSH (p > 0.05).
Hyperprolactinemia was depicted in 24.3% infertile females. Prevalence of primary infertility was 76% while that of secondary infertility
was 24% in study group, there was a significant positive correlation between serum TSH and Prolactin levels in infertile subjects with
irregular menstrual cycle (p < 0.05). Conclusion: There was higher prevalence of hyperprolactinemia with normal thyroid function in
infertile patients.
Keywords: Thyroid Stimulating Hormone, Hyperprolactinemia, Infertility.
1. Introduction
2.2 Subjects and Study Population
Infertility is generally defined as one year of unprotected
intercourse without contraception. Approximately 85-90%
of healthy young couples conceive within one year.
Infertility affects 10 -15 % of couples [1].Hormonal
disorders of female reproductive system are comprised of a
number of problems resulting from aberrant dysfunction of
hypothalamic- pituitary-ovarian axis. These relatively
common disorders often lead to infertility. Thyroid
dysfunction which is quite prevalent in the population
affects many organs including male and female gonads,
interferes with human reproductive physiology, which
reduces the likelihood of pregnancy and adversely affects
pregnancy outcome, thus becoming relevant in the algorithm
of reproductive dysfunction.[2-3] Difficulty to conceive or
subfertility constitutes a major psychological burden. Proper
evaluation of these disorders involves multidimensional
diagnostic approach, with a pivotal contribution from
clinical laboratories [4]. Thyroid dysfunctions interfere with
numerous aspects of reproduction and pregnancy. Therefore
measurement of prolactin and thyroid hormones, especially
thyroid stimulating hormone (TSH), has been considered an
important component of infertility work up in women [5]. In
the present study age matched (primary and secondary)
infertile females were compared with normal fertile females
to assess status of prolactin and thyroid stimulating
hormone.
This was a hospital based, analytic, descriptive case control
study, conducted in the Department of Diagnostic and
Research Unit for hormones analysis and evaluation, at
Khartoum teaching hospital, Sudan, from March 2014 to
August 2015. The subjects were selected from the coming
patients to (DRU) outpatients for hormonal studies. After
informed consent, thyroid profile (TSH, thyroxin T4 and
triiodothyronin T3) and serum PRL of all subjects was done
at their first visit. 70 infetirile females (with both types of
infertility) as study group and 30 healthy, fertile females in
similar age range were enrolled as controls. The inclusion
criteria for the selection of cases were diagnosis of infertility
(both primary & secondary) and age between 20-40 years.
The exclusion criteria that were adopted during case
selection were male factor infertility and amongst female
factors were tubal factor, any congenital anomaly of
urogenital tract or any obvious organic lesion. Any history
of thyroid disease or previous thyroid surgery or being on
medications for thyroid disorders or hyperprolactinemia was
also amounted to exclusion for the study. These criteria were
laid down after checking the detailed history of subjects
recorded in a pre-designed data collection sheet in the
Department of (DRU) at the time of sample collection.
Samples were taken for evaluation of serum TSH, T4, T3
and PRL levels.
2.3 Samples Collection and Preparation
2. Materials and Methods
2.1 Reagents
All chemical reagents were purchased from Bio system
company (Spine Company for Analytical material and
chemical Reagents).
Paper ID: NOV163453
Five ml of blood samples were drawn from each individual
of study population and controls group, using standard
venipuncture techniques. Sample was allowed to clot for 30
minutes and then centrifuged at3000 rpm for 10 minutes to
obtain clear, transparent serum. The separated serum was
analysed for serum TSH, T4, T3 and PRL estimation or
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International Journal of Science and Research (IJSR)
ISSN (Online): 2319-7064
Index Copernicus Value (2013): 6.14 | Impact Factor (2015): 6.391
stored at 2-80c for maximum period of 5 days if not tested
immediately. Serum T3, T4, TSH and PRL levels were
estimated using immunoenzymatic method. Before
processing the samples, each method was calibrated. The
normal ranges for serum T3, T4, and TSH and are as
follows: 0.51- 1.58 ng/ml, 4.7-12.8 ug/dl, 0.28-6.28 μIU/ml
and 1.2-19.0ng/ml respectively. These values were used to
confirm abnormal cases and then to find association between
thyroid dysfunction and Prolactin levels. To calculate the
prevalence of hyperthyroidism and hypothyroidism serum
TSH level was considered. When serum TSH was <0.39
μIU/ml hyperthyroidism was diagnosed. When serum TSH
was >3.5 uIU/ml hypothyroidism was diagnosed.
2.4 Statistical Analysis
For the statistical data analysis, descriptive statistics were
used to show the characteristics of the infertile and fertile
females (controls). Means were compared using
independent‘t’
test.
Pearson/spearman
correlation
coefficient, whichever was applicable, has been used to see
the correlation between infertility, PRL and TSH levels. A
two–tailed, at minimum 95% confidence intervals & p value
<0.05 has been considered significant. All the data were
analysed using Statistical package for social science (SPSS)
version 20 (IBM, Chicago, USA).
3. Result
Thyroid hormones
The present study includes 70 subjects with infertility as
case study and 30 ages matched and healthy, fertile females
as control group. Most of the patients were in the age group
of 20-40 years. As shown in [table1] serum T4 levels were
found to be significantly increased in infertile females as
compared to controls (p<0.05) .And serum T3 levels was
increased but not statistically significant (p>0.05) as shown
in [Table1]. Moreover [Table 1] indicated that serum TSH
levels were found to be increased but not statistically
significant in infertile females as compared to controls
(p>0.05). However [Table 2] summarizes the percentage
prevalence of thyroid status in infertile subjects
Serum T3
The mean serum T3 levels in infertile patients were 1.5±0.4
ng /ml against the controls who had mean Serum T3 levels
1.3±0.2 ng/ml (euthyroid = 0.8-2 ng/ml) and both groups are
not statistically significantly different to each other (p value
= 0.510). [Table1]. Out of 70 infertile women, 2 (2.9%) had
higher T3 values than normal against controls, T3 values
than normal.
Serum PRL
The mean prolactin levels in infertile patients were
17.7±25.8 ng/ml against the controls who had mean
Prolactin levels of 20.9±26.3 ng ng/ml (normal = 1.2-19
ng/ml) and both groups are showing not statistically
significant difference to each other (p value = 0.570) [Table
1].
Out of 70 infertile patients, 17(24.3%) had high prolactin
levels (in both types of infertility) against control
group.[Figure1] shows the percentage prevalence of
hyperprolactinemia status in both types of infertility among
test group. Hyperprolactinemia affects all age groups in our
study; Hyperprolactinemia is more common seen in patients
suffering from primary infertility which was found to be
encountered 13 out of 17 patients (76%) than those with
secondary infertility (24%).Hyperprolactinemia was
depicted in 24.3% infertile females in our present study. Out
of the 70infertile females, 76% were suffering from primary
infertility while 24% were suffering from secondary
infertility. There was a negative correlation between serum
TSH and infertility.
Correlation between tow variables TSH and PRL levels:
The Pearson’s correlation coefficient was calculated for
serum TSH and PRL, serum TSH.Table [3] showed that
prolactin level in patients group with irregular menstrual
cycle is correlating positively and significantly with the TSH
level, so by increasing TSH there is increase in the prolactin
level.
Table 1: Mean ± SD of hormone parameters in the infertile
and control group
Variable
Serum TSH
The mean serum TSH levels in infertile female were
1.5±1.3μIU /ml against the controls who had mean Serum
TSH levels 1.2±0.7μIU /ml (normal= 0.28-6.28 μIU/ml) and
both groups are not statistically significantly different to
each other (p value =0.200). [Table1].Out of 70 infertile
females, 2 (2.9%) had higher TSH values than normal
against controls.
SerumT4
The mean serum T4 levels is increased in infertile females
99.6±20.6.3μg/l against the fertile (controls) who had mean
Serum T4 levels 80.2 ±19.2μg /l (normal=4.7-12.8 ug/dl,)
and there was statistically significant different between the
two means (p value =0.000). [Table1].Out of 70 infertile
females, 6 (8.6%) had higher T4 values than normal against
controls.
TSH
T4
T3
PRL
infertile
group
1.5±1.3
99.6±20.6
1.5±0.4
17.7±25.8
Control
group
1.2±0.7
80.2 ±19.2
1.3±0.2
20.9±26.3
P.
value
0.200
0.000
0.510
0.570
P. value <0.05 is statistically significant.
Table 2: Thyroid status in infertile females
Age
No of
Thyroid status
group cases 70 Hyperthyroidism Hypothyroidism Euthyroid
20-40 Percentage
8(11%)
2(3%)
60(86%)
years
(%)
Table 3: Correlation between TSH level and prolactin level
in patients group
TSH
PRL
r
0.688
p
0.000
P. value <0.05 is statistically significant.
Paper ID: NOV163453
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International Journal of Science and Research (IJSR)
ISSN (Online): 2319-7064
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Figure 1: Shows the percentage prevalence of
hyperprolactinemia status in both types of infertility
4. Discussion
Hypothyroidism is associated with increased production of
TRH, which stimulates pituitary to secrete TSH and PRL.
Hyperprolactinemia adversely affects fertility potential by
impairing GnRH pulsatility and thereby ovarian function.
Therefore in every infertile female should be investigated for
TSH and PRL levels regardless of their menstrual rhythm at
the time of initial consultation. In our study the age of
infertile female is range from 20- 40 years, the prevalence of
hypothyroidism in this age group was about 2-4 % [6] which
is found to be 8% by Goswami et al [7] and 20% by Sharma
et al [8], while in our present study this prevalence is 3%
which is no similar to that of finding in above. In addition to
thyroid profile other endocrine hormones like prolactin
should be considered in infertility. Hyperprolactinemia and
hypothyroidism are associated with infertility in females
need more research and studies. Most of the study group
were euthyroid the prevalence was found to be 60(86%) , it
is one of thyroid disturbances which effect regulatory of
menstrual cycle and infertility statues. Thyroid dysfunction
was reported to reduce the likelihood of conception and may
affect pregnancy outcome [9].
Prevalence rate of women with both hypothyroidism and
hyperprolactinemia increased throughout the screening
period. Vidal et al [10] reported that higher prevalence of
hypothyroidism and hyperprolactinemia in infertile women
compared to fertile women, resulting in menstrual disorders
which agreed with Goswami, et al, [7] who stated that
hypothyroidism
is
commonly
associated
with
hyperprolactinemia resulting in ovulatory failure, hence
assessment of serum TSH and prolactin level are mandatory
in the work of all infertile women specially with those with
menstrual irregularities. Several mechanisms have been
proposed for the increased serum prolactin level in primary
hypothyroidism, of these mechanisms, attributed to
increased prolactin secretion under the influence TRH which
stimulates TSH as well PRL secretion[11 -12].Thyroid
hormones themselves may play an important role in the
cause of hyperprolactinemia , Davis et al [13] noticed that
3,5,3,- triodothyronine reduces prolactin messenger RNA
levels in rodents hormones levels resulting in increased
prolactin synthesis. Thyroid releasing hormone (TRH) is
considered as a stimulant factor for rising prolactin level,
estrogen may cause increase prolactin response to TRH that
causes higher prolactin level in women [14].
Hyperprolactinemia is a common endocrine disorder of the
hypothalamic-pituitary axis. It occurs more commonly in
women. The prevalence of hyperprolactinemia ranges from
Paper ID: NOV163453
0.4% in an unselected adult population to as high as 9-17%
in women with reproductive diseases. Its prevalence was
found to be 5% in a family planning clinic, 9% in women
with adult onset amenorrhea, and 17% among women with
polycystic ovary syndrome.[15] Our present study
demonstrated that higher occurrence of hyperprolactinemia
(24.3%) was seen in infertile females. This higher propensity
of hyperprolactinemia is in agreement with the findings of
Kumkum et al who had depicted a prevalence of 46% in
their study [16], It is found also in this study that the
prevalence in agreement with the study done in Sudan by
Hanadi et al who had found that the prevalence rate was
(20.6 %) in their study which included 1685 infertile
women with high TSH, 347 (20.6 %) were with high
prolactin level [17]. Hyperprolactinemia affects all age
groups in our study; Hyperprolactinemia is more common
seen in patients suffering from primary infertility which was
found to be encountered 13 out of 17 patients (76%) than
those with secondary infertility (24%).The author
demonstrated that there was a significant positive
correlation, between TSH and PRL levels in patients group
with irregular menstrual cycle, which was found also by
Cramer and co-workers. Who states that TSH and prolactin
were positively correlated in subclinical hypothyroid women
[18]. This correlation was also documented in a study done
in India in 2009 [19]. However, this cannot be observed
regularly because some studies found that no correlation was
observed between TSH and PRL levels, but they recommend
further studies with a large sample size and long follow-up
that are necessary to validate the variation in TSH and
prolactin levels [20, 21].
5. Conclusion
In the present study there is moderate prevalence of
hypothyroidism in infertile female. These disorders may lead
to menstrual irregularities resulting in infertility. This is also
associated with hyperprolactinemia and these patients are
commonly associated with ovulatory failure. Hence,
assessment of serum TSH and prolactin levels are mandatory
in the work up of all infertile women, especially those
presenting with menstrual irregularities. Since a significant
correlation exists between serum TSH and prolactin levels in
infertile females with irregular menstrual cycle, further
studies with a large sample size and long follow-up that are
necessary to validate the variation in TSH and prolactin
levels.
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ISSN (Online): 2319-7064
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